What is the relationship between an electric current and a magnetic field?
Electricity and magnetism are closely related. Flowing electrons produce a magnetic field, and spinning magnets cause an electric current to flow. Electromagnetism is the interaction of these two important forces.
What happens to a compass needle near an electric current?
When a magnet is brought close to it, the needle gets deflected. When an electric current passes through a wire, it behaves like a magnet. This magnetic effect of the electric current makes the compass needle deflect from the north-south direction.
What does a compass tell you about what is happening in the wires?
We use a compass to tell us relative direction of the charge. Charge flows through the wire. What happens in the wires when the battery connections are reversed?
Does a compass always point north?
While a compass is a great tool for navigation, it doesn’t always point exactly north. This is because the Earth’s magnetic North Pole is not the same as “true north,” or the Earth’s geographic North Pole . As the Earth’s magnetic field changes, the magnetic North Pole moves.
How does a wire affect a compass?
Every electric current produces magnetism. Since the compass needle is also a magnet, the magnetic field around the wire attracted and repelled the ends of the compass magnet and caused it to move. You have seen that electricity flowing through a wire can cause a magnet to move. This is called the motor effect.
Where is Earth’s magnetic field the weakest?
equator
Where is the field the strongest Where is the field the weakest?
Where the field lines are close together the field is strongest; where the field lines are far apart the field is weakest. If the lines are uniformly-spaced and parallel, the field is uniform. Another way to visualize field is to use field vectors, which are uniformly spaced.
Which point has the strongest electric field?
Electric field strength is greatest where the lines are closest together and weakest where lines are furthest apart. 5.
Can field lines cross each other?
Electric field lines cannot cross. If they did, they would be telling you that the force on a charge at that location would point in two different directions, which does not make any sense at all. Equipotential lines at different potentials can never cross either.
How do you know the direction of an electric field?
For example, if you place a positive test charge in an electric field and the charge moves to the right, you know the direction of the electric field in that region points to the right.
Is electric field in the same direction as current?
In general the electric field and the current are not in the same direction. Careful here. Th direction of Positive charge is defined by the direction of the field.
What is the relationship between voltage and electric field?
The relationship between the electric field and the voltage difference (derived in the lecture) is given by the following equation: the voltage difference between two points is equal to the integral of the dot product of the electric field and the infinitesimal distance between those two points.
What are the strength and direction of the electric field?
The direction of the electric field due to positive point charge is always acts away from the point charge and electric field due to the negative charge acts towards the negative charge. The electric field is a vector quantity. They cannot be added directly, but can be added vectorially.
What is electric field strength measured in?
The derived SI units for the electric field are volts per meter (V/m), exactly equivalent to newtons per coulomb (N/C).
How do you solve electric field?
In vector calculus notation, the electric field is given by the negative of the gradient of the electric potential, E = −grad V. This expression specifies how the electric field is calculated at a given point. Since the field is a vector, it has both a direction and magnitude.